1. Field of the Invention
The present invention relates to a finder equipped with a focusing indicator and, in particular, to a finder equipped with a focusing indicator having, for example, an index based on an average size of human faces, in which focusing is easily performed by matching the apparent size of an object, which changes depending on the object position, with this index.
2. Description of the Prior Art
Known as conventional finders having a range finder are not only those having an authentic trigonometric range finder equipped with a focusing window, but also a finder with a focusing indicator in which, while an index having an apparent size of an object image corresponding to a focal length is displayed within the finder, the apparent size of the index is changed according to the object distance, and the taking lens is moved along the optical axis in response to the change in size of the index. In such finder with a focusing indicator, the distance to the object can easily be measured by matching the apparent size of the object image, which alters as the object position changes, with the size of the index.
In such finder in which the size of the indicator changes, however, it is necessary to install a lens for changing the apparent size of the index or a mechanism for moving the index within the finder, and a mechanism for interlocking the movement of the index or lens with the movement of the taking lens is further necessary, thus complicating the focusing mechanism. Consequently, it may become problematic in terms of space and cost.
Recently, on the other hand, as films attain a higher sensitivity and cameras have a smaller size, the brightness of taking lenses has become darker, and as the lenses have a shorter focal length, the depth of field has become greater, thus allowing camera systems to be constructed with a range finder precision which is not so strict.